ALSA: hda: Expose codec cleanup and power-save functions

With few changes, snd_hda_codec_set_power_save() and
snd_hda_codec_cleanup_for_unbind() can be re-used by ASoC drivers.
While at it, provide kernel doc for the exposed functions.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20220214101404.4074026-5-cezary.rojewski@intel.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>